This application relates generally to medical equipment and more particularly to an ankle hitch which is mounted to the foot of a patient so that a tensioning mechanism may be attached to the ankle hitch for applying traction to the patient's leg.
Fractures and dislocations of leg bones and joints are desirably treated by applying a continuous longitudinal tension forced to the leg. Such traction eases the patient's pain, improves circulation in the injured leg and minimizes further injury to tissues which surround the injury, such as nerves and blood vessles, by the fractured ends of bones.
Traction may first be applied by emergency para-medics soon after they arrive at the scene of an injury. For this purpose, an ambulance is equipped with a traction splint which serves not only to immobilize the leg but additionally, extends beyond the bottom or sole of the patient's foot so that a resilient means, such as a spring, may be mounted in tension between the lowermost end of the splint and an ankle hitch secured about the patient's foot.
Traction is also a hospital treatment and is conveniently accomplished by means of a cable passing over a pulley which is rotatably mounted to the bed frame. A weight is attached at one end of the cable and the ankle hitch is attached at the other.
One ankle hitch currently being marketed comprises a pair of straps stitched together in a tee shape. It is operatively attached to the foot with the perpendicular strap extending downwardly over the posterior heel prominence into attachment with the tensioning device. Another currently marketed ankle hitch is a boot-like device mounted to a plate. Still other prior art devices are illustrated in the following U.S. Pat. Nos.: 2,723,663; 2,811,965; 3,612,046; 3,680,551; 3,720,206 and 3,762,403.
Each of these prior art devices is limited by one or more of several disadvantages. Many of the prior art devices fail to apply the traction force as a vector lying along the longitudinal axis of the associated leg of the patient without also applying a bending moment to the patient's foot. Such a bending moment rotates the patient's foot away from its comfortable natural position substantially perpendicular to the leg. For example, the strap of the tee shaped device described above which passes over a heel prominence applies an extreme pressure to the heel prominence, rotating the instep of the foot upwardly and causing hypertension of the Achilles' tendon. A similar twisting or rotation affect is caused by the device illustrated in U.S. Pat. Nos. 3,680,551 and 3,720,206.
Other ankle hitches which are capable of applying the tension force vector along the longitudinal axis of the leg, such as that shown in U.S. Pat. Nos. 3,612,046 fail to inhibit the rotation of the foot. What is needed is an ankle hitch which confines and retains the foot in a natural, comfortable position and simultaneously causes the traction force vector to be applied along the longitudinal axis of the leg.
Another deficiency of several of the prior art devices is that they permit the application of excessive compressive forces to the skin which restrict the blood circulation in the surface capillaries and eventually produce surface sores. For example, the strap of the tee shaped device described above will apply such pressure to the heel prominence causing a bed sore wound to this portion of the body.
The tee shaped device, like some other devices, also involves the risk that the strap will slip sideways from the heel prominence and allow dislocation and misalignment of the ankle hitch and frustration of the traction function.
Still other ankle hitches are limited in their practical value because their structure inherently requires that a variety of sizes be available for accommodating different sizes of feet and for accommodating a shoe being worn by the patient.
Finally, as with many medical accessories especially those devices used in emergency situations, it is desirable that the ankle hitch be easily and quickly installed with a minimum of patient movement being necessary.